PyKX could not establish an IPC connection in the Flask app

[rocuinneagain]

Hi, What version of PyKX are you using?

.pykx.i.isw has been renamed to .pykx.util.isw since 2.0.0

[supersaiyanraj]

I tried in pykx 1.6.3

pip list | grep pykx

pykx 1.6.3

after updated the package into 2.2.0 – It make a IPC connection, Thanks a lot.

[ryanas]

Hey, I have issue when I setup the flask server like you described, I managed to get the response, but also got error logs like in the image attachment. Do you know something about this?

[rocuinneagain]

See: PYKX_SKIP_SIGNAL_OVERWRITE on

https://code.kx.com/pykx/2.2/user-guide/configuration.html

*New in 2.2.1

[ryanas]

Thanks for your answer, ! However, I still find the same error logs even with that config enabled. Not sure if this affects the issue, but I am using Flask 3.0 and PyKX 2.2.1. I have tried using other frameworks such as Django or FastAPI, and both are running fine. So, I wonder whether this problem is specific to Flask.

[rsedman]

Did you manage to find a solution for this? I have the same issue!Running flask==3.0.0 and pykx==2.2.1

[supersaiyanraj]

Hello ,I tried the same with both pykx 2.2.0 /2.3.0 , python 3.10.9 , Flask 3.0.2, I can’t able to connect with port 5000.

from flask import Flask 
import pykx as kx 
import json as j 
app = Flask(__name__) 

@app.route("/") 
def hello_kx(): 
     import pykx as kx 
     qcon=kx.QConnection(host='localhost', port=5000) 
     tables=qcon("tables[]").py() 
     import json as j 
     print(j.dumps(ports)) 
     return tables 

if __name__ == '__main__': 
     app.run(host='127.0.0.1', debug=True, port=8100)

I got this error:

if q(‘{.pykx.util.isw x}’, self).py():

File “/rxds/rxds_offerings/datagen/env/lib/python3.10/site-packages/pykx/embedded_q.py”, line 226, in __call__return factory(result, False)

File “pykx/_wrappers.pyx”, line 507, in pykx._wrappers._factory

File “pykx/_wrappers.pyx”, line 500, in pykx._wrappers.factory

pykx.exceptions.QError: .pykx.util.isw

the same code I just run python without flask it return values.

import pykx as kx 
import json 

def hello_kx(): 
     qcon=kx.QConnection(host='localhost', port=5000) 
     tables=qcon("tables[]").py() 
     import json 
     return json.dumps(tables)

a=hello_kx() 
print(a)

[rocuinneagain]

Or if you only use PyKX for querying then you can use in unlicensed mode

https://code.kx.com/pykx/2.3/user-guide/advanced/modes.html#operating-in-the-absence-of-a-kx-license

from flask import Flask 
import os 
os.environ['PYKX_UNLICENSED']='true' 

import pykx as kx 
import json as j 
app = Flask(__name__) 

@app.route("/") 
def hello_kx(): 
    #import pykx as kx 
    qcon=kx.QConnection(host='localhost', port=5000) 
    tables=qcon("tables[]").py() 
    #import json as j 
    #print(j.dumps(ports)) 
    return tables 

if __name__ == '__main__': 
    app.run(host='127.0.0.1', debug=True, port=8100)

[rocuinneagain]

You example will run if you wait and only import pykx within the app

from flask import Flask 
#import pykx as kx <-- remove this 
import json as j 
app = Flask(__name__)

@app.route("/") 
def hello_kx(): 
    import pykx as kx 
    qcon=kx.QConnection(host='localhost', port=5000) 
    tables=qcon("tables[]").py() 
    import json as j 
    print(j.dumps(ports)) 
    return tables 

if __name__ == '__main__': 
    app.run(host='127.0.0.1', debug=True, port=8100)

[rocuinneagain]

We added some functionality in version 2.3.0

https://code.kx.com/pykx/2.4/release-notes/changelog.html#pykx-230

If you enable beta features as well as pykx threading all calls into q from any python thread will be run as if they were calling from the main thread which allows python multithreaded programs to use IPC connections in licensed mode.

You can enable this functionality like this:

import os
os.environ['PYKX_THREADING'] = '1'
os.environ['PYKX_BETA_FEATURES'] = '1'
import pykx as kx

You will also want to ensure that kx.shutdown_thread()​ is called when the script finishes. The safest way to do this is within a try​ – finally​ block like this.

if __name__ == '__main__':
    try:
        main()
    finally:
        kx.shutdown_thread()

More information about this functionality and an example can be found within our documentation:

https://code.kx.com/pykx/2.4/examples/threaded_execution/threading.html